PREPARATION OF SUBSTITUTED IMIDAZOLIDINONES AND HYDANTOINS BY RING-EXPANSION OF AZIRIDINONES

Reaction of 1,3-di-tety-butylaziridinone and other di-tert-alkylazirid inones with cyanamides produces an imidazolidinone (3 or 6) bearing th e tert-alkyl substituents at positions 1 and 5 only, by selective clea vage of the acyl-nitrogen bond. Treatment of the product from the unsu bstituted cyanamide (3) with HNO2 furnishes the corresponding hydantoi n (5), whereas treatment with alkyl halides and base affords another i midazolidinone (7).